1. Field of the Invention
The disclosures herein generally relate to a management system, a communication system, a data management method and a computer readable recording medium storing a program for causing a computer to execute a process.
2. Description of the Related Art
Communication systems that perform a telephone call, a video conference or the like via a communication network such as the Internet or a dedicated line have become popular in recent years due to a demand for reducing travel costs and time of parties. In such a communication system when communication starts between communication terminals, content data such as image data or sound data are sent/received, thereby realizing communication between bases. Moreover, in order to perform the communication between bases smoothly, a method for sharing other content between bases in addition to content for a telephone call has been proposed.
For example, Japanese Patent No. 4241053 discloses a method for controlling a session so as to send/receive sounds to/from a terminal device of a communication partner, and furthermore for controlling a session so as to send/received images or handwritten data to/from the terminal device of the communication partner, thereby realizing voice sound with indicating images. Moreover, Japanese Patent No. 4241053 discloses a terminal device provided with a secondary storage device including a non-volatile memory such as a flash memory or a hard disk. The secondary storage device stores data such as handwritten data that is not desired to be lost even when the power is turned off.
On the other hand, Japanese Unexamined Patent Application Publication No. 2014-93582 discloses a method for comparing content of participation authentication information received from a participation request terminal with content of participation authentication information registered in a terminal management table in a management system, and if both contents coincide with each other, allowing participation of the participation request terminal in a session that is being established.
However, there is a problem that even if a restriction is put on participation in a session, when content data sent/received in the session are managed by a management unit, by accessing the management unit, the content of the session, participation of which is restricted, can be disclosed to an access source that does not participate in the session.